Brassieres are commonly made with two cups, two shoulder straps, two back straps, a latching mechanism (hooks and eyelets), optional padding (soft foam, air, water, gel, or silicone), and, optionally, two underwires. Padding can come as removable inserts or as an integral part of the bra. Some bras comprise extremely delicate fabric, such as lace, satin, silk, mesh, high-tech microfiber, stretch, and sheer fabric.
Thus, it is desirable to have a device which provides protection for the bra during a washing cycle in a conventional clothes washing machine. Preferably, the washing device also assists in maintaining the overall shape of the bra during a washing cycle. The washing device also preferably prevents any underwire from puncturing through the fabric of the bra and ruining the bra. One such bra washing device is shown in U.S. Pat. No. 6,742,683. The washing device of this patent consists of an outer shell with two shell portions which are hinged together along one side of the shell portions and which have a latch along an opposite side of the shell portions. The shell can thus be opened to insert a bra to be washed, and then the shell can be latched in a closed condition prior to placing the washing device in the washing machine. When washing is completed, the shell can be opened via the latch to remove the washed bra.
The hinge structure of such a bra washing device includes knuckles or projections which extend outwardly along a portion of the mating edge of each shell portion. These knuckles have a small internal bore into which a metal hinge pin is inserted during manufacture of the device. Normally, a frictional fit between the internal bore and the hinge pin will keep the hinge pin in place in the internal bore. However, when the washing device is inserted into a washing machine, the water and detergent in the washing machine reduce the friction between the hinge pin and the internal hinge bore. Also, the pounding of he device by the agitator of the washing machine can dislodge the hinge pin and cause it to migrate out of the bore. Thus, the hinge pin may begin to slide partially or entirely out of the internal hinge bore. Of course, if the hinge pin is partially out of the hinge bore, it may catch or snag on other clothes with the potential to damage or ruin the clothes. On the other hand, if the hinge pin comes entirely out of the bore, the washing device may open far enough to discharge the bra out of the device during the wash cycle. If the hinge pin slides out of the internal hinge bore, damage could also result to the washing device, particularly around the latch of the device.
Various means have been tried to prevent the hinge pin from migrating out of the internal bore in the plastic hinge. For example, a raised knurl at the entrance to the internal bore may keep the hinge pin in place due to the greater friction against the hinge pin. However, manufacturing tolerances of the knurl and of the internal bore may cause excessive stress in the plastic material of the hinge, which may cause the plastic to crack at a later time. The cracked hinge may be unsightly, may cause damage to other clothing in the washing machine, and/or may nevertheless cause a reduction of friction with the hinge pin and permit the hinge pin to migrate out of the internal bore. Thus, knurling of the plastic material is not a satisfactory solution to keeping the hinge pin in its internal bore.
Heretofore, heat staking attempts were made to fill an end of the hinge pin bore to prevent or block the hinge pin from sliding out of the bore. For example, a similar or compatible plastic material to that of the washing device was melted about and into an end of the bore with a heat source, such as a soldering iron. Frequently, the plastic filling material did not properly adhere to the plastic about the end of the hinge pin bore. In other instances, the agitation which a bra washing device experiences in a washing machine caused the fusing of the plastic materials to fail. Thus, fusing of the plastic materials around the entrance to the internal bore has also proven to be an unsatisfactory solution to retaining the hinge pin in its bore.
Moreover, after melting plastic about the hinge pin bore to block the hinge pin from sliding out, the melted plastic was typically irregular, requiring further finishing of the appearance of the melted plastic. For example, sanding or grinding was frequently required to provide a presentable final product, and to remove any rough edges of the melted plastic which could damage other clothes in the washing machine. This manual melting and finishing work was time consuming, and, therefore, an expensive portion of the overall manufacturing cost of the washing device.
It is therefore an object of the present invention to prevent a hinge pin from migrating out of the internal bore of a hinge, especially in a washing device.
Another object of the present invention is to provide a method of retaining a hinge pin in an internal bore of a hinge which is easy to teach and easy to accomplish, even by relatively unskilled production workers.
A further object of the present invention is to reduce the time and cost of manufacturing a bra washing device, thereby enabling greater efficiencies and higher volumes of manufactured product.
Yet another object of the present invention is to provide a simpler method of retaining the hinge pin in the hinge of a washing device which facilitates outside sourcing of the manufacture of the washing device.